El Cortez, Downtown
Where the crack whore meets the bum, but at least one of the last places to play real (3:2) single-deck blackjack. Pretty easy to make some decent money, when you're counting cards, but if you don't leave within 1 hour of playing, their security might show you their backroom
Would't stay at their hotel-rooms though... The Flamingo (Strip) and the Golden Nugget (Downtown) are my choice.